Denning, Arkansas has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 9.8 °C (low) to 22.1 °C (high). Annual precipitation averages 1268.5 Millimeters. Denning is located in USDA Plant Hardiness Zone 8a. The growing season typically runs from the last frost around Mar. 21 - Mar. 31 through the first frost around Nov. 1 - Nov. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -1.8 °C | 9.7 °C | 89.66 mm |
| February | 0.1 °C | 12.3 °C | 77.72 mm |
| March | 4.3 °C | 17.1 °C | 113.79 mm |
| April | 9 °C | 22.3 °C | 117.6 mm |
| May | 14.4 °C | 26.3 °C | 147.32 mm |
| June | 19.1 °C | 30.8 °C | 102.36 mm |
| July | 21.1 °C | 33.4 °C | 96.77 mm |
| August | 20.6 °C | 33.3 °C | 92.2 mm |
| September | 16.5 °C | 29.4 °C | 97.03 mm |
| October | 9.9 °C | 23.3 °C | 107.95 mm |
| November | 4.2 °C | 16.6 °C | 124.21 mm |
| December | -0.2 °C | 10.8 °C | 101.85 mm |
| Annual | 9.8 °C | 22.1 °C | 1268.46 mm |
| Average First Frost Date | Nov. 1 - Nov. 10 |
| Average Last Frost Date | Mar. 21 - Mar. 31 |
| Average Days With Frost | 50-75 Days |
| Plant Hardiness Zone | Zone 8a : -12.2°C to -9.4°C |
| Plant Hardiness Zone - 2012 | Zone 7b : -15°C to -12.2°C |
| Current Drought Conditions | Moderate Drought |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |